No clue about air travel. But if you can get there:
check out American Casino Guide or Las Vegas Advisor coupon books. Should have a two-for-one or three-for-two room coupon for some place downtown. Shuttle from the airport should be under $30 round trip. Use the coupon books and promotions they give to new members and you should earn at least $100. There will be other promotions in those books that give you dining credits for 200 or 300 slot points. Learn video poked and you can eat very cheap (with a shot at a Royal or quads), if you drink, play at the bar very slowly
If you're desperate to gamble, either sports or poker. If you're playing black jack and the count goes to +4, how much can you really get down with enough to split or double? Sports at least you can watch the game for a couple hours of action. There are some good short stack poker strategies (again if you drink, this will be the time to do so, since they will be comped): buy in for $40 against big stacks, wait until you have AA, KK, QQ or AK and try to get a caller for half your stack. Then go all-in after the flop. Win or lose walk away